嘉绍跨江大桥双壁钢吊箱围堰施工  

Construction of Double-Wall Steel Suspension Cofferdams for Jiashao Bridge

作　　者：代强波 钟海 周爱兵 

机构地区：[1]中铁大桥局嘉绍跨江大桥项目经理部,浙江海宁314415 [2]嘉绍跨江大桥工程建设指挥部,浙江绍兴312366

出　　处：《桥梁建设》2010年第A01期33-35,47,共4页Bridge Construction

摘　　要：嘉绍跨江大桥北副航道桥为四跨连续刚构桥,采用群桩承台基础。根据钱塘江特殊的水文地质条件,采用双壁钢吊箱围堰作为基础施工的挡水结构,兼做承台施工的模板。围堰在后场分块制作,现场拼装成整体后,采用4台100 t液压千斤顶下放围堰到设计标高,围堰下放到位后进行围堰封底和抽水施工。为保证涌潮冲刷下围堰的下放安全、封底混凝土浇筑,在围堰侧板上焊接2层围堰导向、在底板布置8个撑杆螺丝以加强横向稳定。目前已有8个围堰完成封底并进行了承台施工,围堰拼装及下放后平面位置偏差符合规范要求,封底一次成功且围堰均不漏水。The north auxiliary shipping channel bridge of the Jiashao Bridge is a 4-span continuous rigid-frame bridge employing group bored pile and pile cap foundations.In the light of the special hydrologic and geologic conditions of the Qiantangjiang River at the bridge site,the double-wall steel suspension cofferdams are used as the water retaining structures that at the same serve as the formwork for the pile caps in the construction of the foundations.A cofferdams is fabricated in sections and is assembled into an integrity in field.The cofferdam is then lowered to the designed elevation by 4 sets of 100-t hydraulic jacks.After the cofferdam is set in place,the cofferdam base is sealed by tremie concrete and the water inside the cofferdam is pumped out.To ensure the safety of lowering of the cofferdam and casting of the tremie concrete under strong tide and scouring,the transverse stability of the cofferdam is reinforced by installing 2 levels of guiding devices on the side plates and 8 strut bolts on the bottom plate.At present,the base sealing of 8 cofferdams has been completed and the construction of pile caps has been carried out.The deviations of the plan positions of the assembled and lowered cofferdams can comply with the relevant requirements in the technical specification.The base sealing of a cofferdam is successfully completed in one time and no water leakage problem has been found.

关 键 词：桥梁基础 双壁钢吊箱围堰 桥梁施工 

分 类 号：U445.556[建筑科学—桥梁与隧道工程]